Things Partner Communities Users Can't Do

Partner Community Gotchas

Things I am spending hours on so that you don't have to!

When you create a new partner community profile, ensure to add it to the Community setup otherwise you get the "No available community" error. See Stackexchnge for the answer.
You can't see Roles in Sharing Settings until you create your first Partner User - yes, very weird, I know!
You need to have the old profiles editor enabled to set up delegated administration. I added some notes here https://success.salesforce.com/ideaView?id=08730000000l0aaAAA&sort=2 as this seems to be completely undocumented!
Transferring ownership of records.
- This is not just a community thing "To transfer ownership of any single record in an organization that does not use territory management, a user must have the appropriate “Edit” permission and either own the record or be above the owner in the role hierarchy"
- They can't if they are in the same role level in the hierarchy.
- They can if they are higher in the hierarchy than the owner of the record.
- They can see all non partner users, and transfer ownership to them - this is not very good.
  - But you could set a validation rule to prevent it (I think).
- They can change the ownership to an owner where they can then not change the ownership again.
- They can change the ownership to an owner where they can never see that record again - not good.
- Granting them superuser access does not help with the ability to transfer records.